A euphemistic term for any material (although most commonly a tissue) used to clean up after oneself post auto-eroticism.
Use in the singular is consistent even if more than one tissue is required for the mop up.
While most commonly applicable to, it is not male exclusive.
After masturbating for the ninth time before noon, David realized this is what his life had amounted to after getting dumped by his half-blind, socially awkward, deaf, mute, perpetually stoned girlfriend.
Considering ending it all there, he gazed down at the mess he had just unleashed and heaved a great sigh. The thought of being found dead covered in his own ejaculate quickly dissuaded him. Reaching for a piece of dignity cloth, he slowly cleaned and pulled himself back together.